.\"	$OpenBSD: disktab.5,v 1.14 2011/09/03 22:59:07 jmc Exp $
.\"	$NetBSD: disktab.5,v 1.4 1994/11/30 19:31:15 jtc Exp $
.\"
.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)disktab.5	8.1 (Berkeley) 6/5/93
.\"
.Dd $Mdocdate: September 3 2011 $
.Dt DISKTAB 5
.Os
.Sh NAME
.Nm disktab
.Nd disk description file
.Sh SYNOPSIS
.Fd #include <disktab.h>
.Sh DESCRIPTION
.Nm
is a simple database which describes disk geometries and
disk partition characteristics.
It is used
to initialize the disk label on the disk.
The format is patterned after the
.Xr termcap 5
terminal database.
Entries in
.Nm
consist of a number of colon
.Pq Ql \&:
separated fields.
The first entry for each disk gives the names which are
known for the disk, separated by
.Dq \&|
characters.
The last name given should be a long name fully identifying the disk.
.Pp
The following list indicates the normal values stored for each disk entry:
.Bl -column "d[0-4]" "bool" "Description"
.It Sy Name Ta Sy Type Ta Sy Description
.It \&ty Ta str Ta "Type of disk (e.g., removable, winchester)."
.It \&dt Ta str Ta "Type of controller (e.g.,SMD, ESDI, floppy)."
.It \&ns Ta num Ta "Number of sectors per track."
.It \&nt Ta num Ta "Number of tracks per cylinder."
.It \&nc Ta num Ta "Total number of cylinders on the disk."
.It \&sc Ta num Ta "Number of sectors per cylinder (default: ns*nt)."
.It \&su Ta num Ta "Number of sectors per unit (default: sc*nc)."
.It \&se Ta num Ta "Sector size in bytes (default:"
.Dv DEV_BSIZE ) .
.It \&sf Ta bool Ta "Controller supports bad144-style bad sector forwarding."
.It \&rm Ta num Ta "Rotation speed in RPM (default: 3600)."
.It \&sk Ta num Ta "Sector skew per track (default: 0)."
.It \&cs Ta num Ta "Sector skew per cylinder (default: 0)."
.It \&hs Ta num Ta "Headswitch time in usec (default: 0)."
.It \&ts Ta num Ta "One-cylinder seek time in usec (default: 0)."
.It \&il Ta num Ta "Sector interleave (n:1) (default: 1)."
.It \&d[0-4] Ta num Ta "Drive-type-dependent parameters."
.It \&b0 Ta str Ta "Pathname to primary bootstrap."
.It \&b1 Ta str Ta "Pathname to secondary bootstrap."
.It \&bs Ta num Ta "Boot block size (default:"
.Dv BBSIZE ) .
.It \&sb Ta num Ta "Superblock size (default: "
.Dv SBSIZE ) .
.Pp
.It \&ba Ta num Ta "Block size for partition"
.Dq a
(bytes).
.It \&bd Ta num Ta "Block size for partition"
.Dq d
(bytes).
.It \&be Ta num Ta "Block size for partition"
.Dq e
(bytes).
.It [...] Ta "" Ta ""
.It \&bp Ta num Ta "Block size for partition"
.Dq p
(bytes).
.Pp
.It \&fa Ta num Ta "Fragment size for partition"
.Dq a
(bytes).
.It \&fd Ta num Ta "Fragment size for partition"
.Dq d
(bytes).
.It \&fe Ta num Ta "Fragment size for partition"
.Dq e
(bytes).
.It [...] Ta "" Ta ""
.It \&fp Ta num Ta "Fragment size for partition"
.Dq p
(bytes).
.Pp
.It \&oa Ta num Ta "Offset of partition"
.Dq a
(sectors).
.It \&ob Ta num Ta "Offset of partition"
.Dq b
(sectors).
.It \&oc Ta num Ta "Offset of partition"
.Dq c
(sectors).
.It [...] Ta "" Ta ""
.It \&op Ta num Ta "Offset of partition"
.Dq p
(sectors).
.Pp
.It \&pa Ta num Ta "Size of partition"
.Dq a
(sectors).
.It \&pb Ta num Ta "Size of partition"
.Dq b
(sectors).
.It \&pc Ta num Ta "Size of partition"
.Dq c
(sectors).
.It [...] Ta "" Ta ""
.It \&pp Ta num Ta "Size of partition"
.Dq p
(sectors).
.Pp
.It \&ta Ta str Ta "Type of partition"
.Dq a
(4.2BSD, swap, etc.).
.It \&tb Ta str Ta "Type of partition"
.Dq b .
.It \&tc Ta str Ta "Type of partition"
.Dq c .
.It [...] Ta "" Ta ""
.It \&tp Ta str Ta "Type of partition"
.Dq p .
.El
.Sh FILES
.Bl -tag -width /etc/disktab -compact
.It Pa /etc/disktab
.El
.Sh SEE ALSO
.Xr getdiskbyname 3 ,
.Xr disklabel 5 ,
.Xr disklabel 8 ,
.Xr newfs 8
.Sh HISTORY
The
.Nm
description file appeared in
.Bx 4.2 .
